PROLINE PEPTIDE ISOMERIZATION AND THE REACTIVATION OF DENATURED ENZYMES

The kinetics of slow phase reactivation of 11 single chain denatured enzymes containing between 6 and 28 proline residues were each found to be first-order having half-times ranging from 0.15 to 12.1 minutes, respectively, at 25 °C. The reactivation kinetics of selected enzymes are independent of solvent viscosity and give an activation energy of 19 kcal/mol. These results are consistent with the proposal that cis/trans proline isomerization in the denatured state is responsible for the slow phase of enzyme refolding/reactivation and with biosynthetic rates for enzyme production. © 1979.